In the course of producing oil and gas wells, typically after the well is drilled, the well may be completed. One way to complete a well is to divide the well into several zones and then treat each zone individually. Treating each section of the well individually may be accomplished in several ways.
One commonly used way of accessing the area to be treated is referred to as plug and perf. Generally, when plug and perf is used a perforating assembly is prepared on the surface. The perforating assembly typically consists of a plug on the lower end of the assembly, a setting tool just above the plug, and a perforating gun just above the setting tool. The assembly is then run into the wellbore to some point below the first zone that the operator desires to treat. The setting tool is then activated locking the plug into place and sealing the well below the plug against fluid flow from the surface or the well above the plug. The setting tool is then disconnected from the plug allowing the setting tool in the perforating gun to be moved to a point adjacent the first zone that the operator desires to treat. The perforating gun is then activated penetrating the casing to allow access to the first zone. The process is then repeated to allow access to each additional zone.
One of the difficulties with the plug and perf method is that the plug has very thick walls in order to support the compressive loads that are applied which allow the slips to dig into the casing wall when the slips are set. In order to immediately put the well on production after the well treatment, such as fracking, is complete operators tend to prefer plug that is a hollow throughbore that can be sealed with a ball during well treatment. The ball can then be removed by reverse flow or dissolution allowing the well to be put on production. Unfortunately, in order to meet the requirement that the plug must support the compressive loads as the slips are set, again the walls must be very thick in turn greatly reducing the diameter of the through bore through which fluid is produced. It is not uncommon for a conventional plug to have a through bore with less than half the diameter of the outer diameter of the plug.